Searchlight



E. J. MURPHY ET AL SEARCHLIGHT Feb. 15, 1927. 1,618,103

Original Filed May 17. 1920 4 leg i CONTACTS CONTROLLED BY W183 u 6 I82 I TH E RMOSTAT Invent ors:

Edwin J. Murph Leonard P Hut y M Z Their Attorney Patented Feb. 15, 1927.

PATENT QFFWB :spwm ninunrnr AND LEONARD r. rin'r'r,

" sIGnoRs roernnnnnnfnr ncrnro COMPANY,

OF SCI'IENECTADY, NEW YORK, AS- A CQRPORATION OF NEW YORK.

SEARGHLIGHT.

lOr i gi nal'applicati n fi1ed May 192a, serial No. 381,904. Divided. and this application filed December 19,1924. Serial No. vsaeoe.

This application is a division of our pending application, Serial No. 38130 1, filed'Ma-y lamp making it ":Our invention relates to electromagnetic means, and more in particular it relates to electromagnetic means that are especially in connection with an' are possible to secure reliable automatic. control of the electrodes. The electromagnetic device ofour invention is adapted also to control the striking of the arc by causing the negative electrode to be separated from the positive electrode and adaptedfor, use

also to control'thefeeding operations of the 'negativeelectrode as will more fully apv The-i vention will be readily understood hyreierri-ng to theaccompanying drawing electromagnetic in whichFig. 1 is tion oi the circuits used in connection with the arcotour prior application and otthe device' of our invention;

Fig.2 isfaside view'of the electromagnetic device. 1 2

' application whenv the current theelectrodes are left in contact and when the current is turned on withdrawing. the negative electrode asuit- "disclosed in onr said prior lamp is .turned ofi In the the arc is struck by able distance.

'In thesaid prior application a feeding mechanism is provided, through the medium of which the negative electrode may be fed toward the positive electrode to compensate for the consumption due .to the arc or the negativeelectrode may-be backed away from the positive electrode incase the distance between'the electrode hasbeen reduced more a p air-of solenoids not shown;

than the proper amount;

The mechanism foraccomplishing these feeding operations 189 and 1 13, Fig. 1. Each of these solenoids is prcvidedwith a core ;.'which is slidably keyed upon a driving shaft, As shown, the solenoid 1139] 1S provided with'a core 138 and the solenoid ,143'i's provided with ajcore 142. The core similar driving cone. 14:5.

138 is provided in turn with a drivingcone the core 1 12 is provided with a solenoids is energizer l5 the driving cones bea diagrammatic illustra-- is underthe control 01 I Between these cones there is provideda cone .146which is The arrangement of this device is such that when neither of the solenoids is energized the cone 146 is not driven and, consequently the electrode 97 is not fed.

By means of the electromagnetic device of our invention the solenoids 139 and 1 13 are automatically controlled to maintain the negative electrode in its proper position in order that the arc ma be'iri'aintain'ed in a constant condition. solenoids is accomplished through' the medi um of the armature 156 of theelcctromagnetic device. Furthermore, through the medium of the armature 152 of the same devicethe arc is drawn between the electrodes 97 and when the current is turned on through the lamp.

A more detailed description oi the invention follows: The are is started by energizing the electromagnet 148 which is in series with the electrodes and receives current from the main line 149. The armature 152 carries thearm 15 1 (see Fig. 2) the forward end of which is pivotally joined to a length (not shown) 'to which length the negative electrode 97 is secured. When the electroinagnet 1418 is energized the armature 152 is attracted and consequently the negative electrode 97 is operated from the positive electrode and the are thereby starts. 7

The electromagnetic device is provided portion 150 turned down'and cut away in order to reduce the cross section thereof.

This reduced section become lllQIQSfltlllEttQd. than the larger age flux; which is used armature .156. This "armature is pivotally supported to fixed standard 155. I The forward end of the armature 156' carries'a don The control of thetwo sections andpr'oduc'e's a leakfor operatingthe tact 1.57 arranged to play between two fixed but adjustable contacts 158 and 159. This armature is counterbalanced by a weight 160 secured to the opposite end by means of a brass strip 161.

Near the contact end of armature 156 there is pivoted an arm 162 of non-magnetic material, the arm extending backward to ward the upright 155 and is at its rear end turned upward and there carries a screw 163 which holds one end of the helical spring 164, the other end of which spring is secured to the standard 155. The tension of the spring can be adjusted by means of the screw. It will be seen that the armature 156 is provided with a perforation in line with both the adjustable stop 165 and the 1 fixed stop 166. The adjustable stop 165, it.

will be seen, is mounted on the arm 162, while the fixed stop 166 is secured to the restricted portion 150 of the yoke. Another adjustable stop 167 is provided on the armature 156 in the path of the arm 162.

The fixed contacts 158 and 159 are connected with the solenoids 139 and 143 by conductors 168 and 169. At a point between the solenoids 139 and 143 along the conductor 170 a connection is made to a switch 171 through the medium of which connection is Inadeby way of contact 171 with the conductor 172 and with the negative main 149. On the other hand the armature 156 is connected by conductor 173 with the positive side of the main 149.

The operation o1 the relay system for the automatic control for the negative electrode depends upon the difierence in pull upon the armature 156 by the leakage flux on the one hand and the spring 164 on the other. The magnetic pull depends upon the air gap be tween the armature 156 and the yoke.

In working out this electron'iagnetic de vice it was found advisable to provide a small non-magnetic gap 151 between the core 148 and the head 151. This prevents too high a saturation of the whole magnetic circuit and improves the sensitiveness of the relay to changes in the exciting current.

'IVhen the normal current the lamp the armature 152 is attracted and the forces are so balanced that the contact 157 touches neither of the contacts 158 nor 159 and the stops 165 and 166 are in contact the arm 162 bearing upon the stop 167. The adjustable elements 15 158, 159, 163, 165 and 167 are adjusted to establish this condition. Slight variations of current do not perceptibly affect the conditions of the equilibrium of the armature 156. But it the current strength is reduced to a considerable degree the leakage flux is perceptibly diminished and the armature 156 promptly responds so that the spring 164 over-balances the magnetic pull to the extent that the armature 156 rises and contact 157 strikes the passes through fixed contact 158. By this action the stop 165 rises above stop 166 but the arm 162 continues in contact with stop 167. In this condition of the apparatus the lever 156 is in quasi-equilibrium and contact 157' is only returned to its middle position when the current again rises to its normal strength.

When the current for any reason rises perceptibly above its normal strength the magnetic pull overpowers the pull of the spring 164 and the armature 162 descends until contact 157 strikes contact 159 and is there again in quasi-stable equilibrium. By this downward movement of lever 156 the stops 165 and 166 are maintained in contact, the latter now acting as a secondary pivot but the arm 162, pulling the spring 164 and turning about its pivot near the free end of the armature 156, is raised from step 167.

In the operation and for the preservation of the quasi-stable equilibrium of contact 157 in its three positions the directing of the axis of spring 164 is important. This axis (in the line of which the spring primarily acts) is indicated by the dotted line as, and it will be noticed that it passes above the pivot of arm 162; moreover, the direction of this axis can be adjusted by the stop 167. lVhile the resultant course of spring 164 is in the line of its axis only a component of this force, at right angles to the axis, acts upon the arm 162 to turn it about its principal and secondary pivots thus maintaining its contact with stop 167. This component increases with the angle which the axis of the spring forms with the line connecting the point of central attachment of the spring 011 standard 155 with the pivot of arms 162 and the greater this component, the greater must be the magnetic pull on armature 156 to balance or to overpower the same. For this reason the contact 157 can be moved from any of its three positions because of the current through the coil 148.

It will be seen therefore that through the medium of the electromagnetic device, when ever the arc becomes too elongated, the solenoid 143 comes into operation and causes the negative electrode 97 to advance and thus reduce the length of the arm. On the other hand, if for any reason the arc becomes too short the increase in current through the coil 148 causes the solenoid 139 to come into play with the result that the negative electrode is withdrawn. The withdrawing operation will continue until the arn'iature 156 breaks the circuit through the solenoid 139 and the advancing operation as a result of the energization of the solenoid 143 continues until the armature 146 breaks the circuit through solenoid 143. s long .as the arc is of the proper length the armature 156 retains its balanced position midway between the contacts 159 and 158 and the feeding operations of the negative electrode are suspended,

stablejequilibrium, magnet, anal-mature affording a path ""What'iwe-claim as new and desiretosecure by-LettersPatent of the United States,

thegileakage fluxand carrying a'movable "electric contact, said electromagnet having a reduced core section under said armature,

twozcontacts in -thewpath otthe movable con- I: thev action of the transverse components of tact, an arm pivoted to the armature, a

" springiexeitmga' pull upon thearmgin a direction above its pivot, and two stops for theuarm, whereby the lat-teris subjected to the: pull of the spring and thereby reacts upontthe. armature.

,2. In"combination, an electroma'gnet, an

armaturetherefor, anarmpivoted on said armature, a stop for the arm 7 for limiting the-rotation o-f'the arm with respect to the armature, and a=.stop' independent or the y armature .ior causing the rotation of the amuwith respect to the armature when the armature is operated by the magnet.

3, :In acircuit controlling device, a magnet, an armature for said magnet, an arm pivoted Lon 'thearmature, and a resilient element'forexertinga pulling force upon said armaturezthrough the medium of said arm and a pair of trollin the amount of force exerted tween pivoted on the armature,

stops for thearm for controlling the amount of force exerted by said resilient'element upon said armature through said arm.

4.7In a circuit controlling device, a magnet, an armature for said magnet, an arm pivoted on the armature, and a resilient element for exerting a pulling force upon said armature through the. medium of said arm, and a pair of stops for the arm for conby said resilient element upon said armature through said arm, one of said stops being interposed between'thearm and the armature.

. 5'. In a circuit controlling device, amagnet, an 'armatureifor said magnet, an arm pivoted onthe armature, and a resilient element for exerting a pulling force upon said armature through the medium oi said arm, and ,a pair of stops for the arm for controlling the amount of force exerted by said resilientelement upon said armature through said arm, one of said stops interposed bethe arm and the armature, and the other of said stops being mounted independently of said armature.

6; In a circuit controlling device, a magnet, an armature for vsaid magnet, an arm and a resilient element for exerting a pulling force upon said armature-through the medium of said arm,

pair of stops for the arm for corn of force exerted by said and a trolling the amount ture in the opposite direction advance the armature Q F resiliente'lement upon said armattu'e through said arm, and a pair or circuit contacts 10- cated ore on one side of thearmature and the other on the other side o l the armature and located in operative relation to the armature whereby the ,armature may close the other a connection with either one or or said contacts;

7. In combination with. a magnet, an

armature for the magnet mounted to rotate 1 about an axis otiset from said first axis, said 7 contacts serving also one to limit the rotationof the armature in one. direction and the other to limit the rotation of the armaibout its axis, a stop for the arm :locatedbetween thearm and the armature dfor limiting the rotation oi the armabout its axis with respectzto the armature, and a second stop. mounted independently of the armature torcausing rotation of the arm aboutits axis to the armature, and a resilient element'connected to said arm for exercising a pull on the armaturethrough said arm in opposition to the pull of the magnet, said iresilientele ment being adapted to bring the armature into engagement with the first one of sai contacts when the magnet is deenergized, said magnet being adapted when energized to exert a pulling force on said armature to disengage said armature from said first contact, and to advance the armature until the two stops are brought simultaneously into operation, said stops serving to bring the armature to a standstill at a particular point between said contacts, said magnet being also adapted when energized more strongly to beyond the intermediate stop position into engagement with the second one of said contacts.

8. In combination with a magnet, an armature for the magnet mounted to rotate about an axis, a first contact on one side 0- said armature, and a second contact on the other side of said armature, said contacts being located in operative relation to said armature whereby electric connection may be made to either one orthe other of said contacts by the operation of the armature, an arm mounted on said. armature to rotate about an axis offset from said first axis, said contacts serving also one to limit the rotation of the armature in one direction and the other to limit the rotation of the armature in the opposite direction about its axis, a stop for the arm located between the arm and the armature for limiting the rotation of with respect.

the arm about its axis with'respect to the armature, and a second stop mounted independently of the armature for causing rotation of the arm about its axis with respect to the armature, and a resilient element connected to said arm for exercising a pull on the armature through said arm in opposition to the pull of the magnet, said resilient element being adapted to bring the armature into engagement with the first one of said contacts when the magnet is deenergized, said magnet being adapted when energized to exert a pulling force on said armature to disengage said armature from said first contact, and into engagement with said second contact with said arm operative in engagement with only one of said stops, said stop serving to increase the tension between said resilient element and said arm whereby when said magnet is weakened the armature is separated by said resilient element from the second contact and returns toward the intermediate position until the second stop of said arm is brought into operation, said second stop serving to reduce the effective. pull of the resilient element and to bring it vinto equilibrium with the pull of the magnet on the armature thereby insuring a stable intermediate position between said contacts for the armature.

9. A circuit controller comprising an electromagnet, a pivoted armature for said magnet, -a pair of contacts located one on each side of the armature and in operative relation to the armature whereby the armature may engage either one or the other of said contacts, an arm pivoted on the armature, the armature and arm forming an armature structure, the axes of the pivots being displaced with respect to each other, a spring under tension secured to the arm whereby the armature and the arm may both be made to rotate about the axes of their respective pivots, a stop for th arm located on the armature structure for limiting the rotation of the arm with respect to the armature and a stop for the arm mounted in operative relation to the arm and stationary with respect to the armature structure for causin the rotation of the arm about .its axis, said stops and said contacts being so disposed with respect to each other that, first, when the armature is in engagement with one of said contacts the arm is free from the restraining action of both stops; second, when the armature is disengaged from both contacts the arm is restrained by both stops whereby the armature may be brought to a stop at a point between the two contacts; and, third, when the armature is in engagement with the second contact the arm is restrained by only one of said stops.

In witness whereof, we have hereunto set our hands this 18th day of December, 1924.

EDWVIN J. MURPHY.

LEONARD P. HUTT. 

